Package org.infinispan.counter.api

Interface CounterManager

public interface CounterManager

The CounterManager creates, defines and returns counters.

It is thread-safe in the way that multiples threads can retrieve/create counters concurrently. If it is the first time a counter is created, other concurrent threads may block until it is properly initialized.

A counter can be defined using defineCounter(String, CounterConfiguration) and isDefined(String) returns if the counter is defined or not.

The counter can be retrieved/created using the getStrongCounter(String) or getWeakCounter(String) to return an (un)bounded strong counter or weak counter. The operation will fail if the counter is defined with a different type. For example, define a strong counter "test" and try to retrieve using the getWeakCounter("test".

Since:

9.0

Author:

Pedro Ruivo

See Also:

• CounterConfiguration

Method Summary

Modifier and Type	Method	Description
boolean	defineCounter(String name, CounterConfiguration configuration)	Defines a counter with the specific name and CounterConfiguration.
CounterConfiguration	getConfiguration(String counterName)
Collection<String>	getCounterNames()	Returns a Collection of defined counter names.
StrongCounter	getStrongCounter(String name)	Returns the StrongCounter with that specific name.
WeakCounter	getWeakCounter(String name)	Returns the WeakCounter with that specific name.
boolean	isDefined(String name)
void	remove(String counterName)	It removes the counter from the cluster.
void	undefineCounter(String name)	It removes the counter and its configuration from the cluster.

Method Details

getStrongCounter

StrongCounter getStrongCounter(String name)

Returns the StrongCounter with that specific name.

If the StrongCounter does not exists, it is created based on the CounterConfiguration.

Note that the counter must be defined prior to this method invocation using defineCounter(String, CounterConfiguration) or via global configuration. This method only supports CounterType.BOUNDED_STRONG and CounterType.UNBOUNDED_STRONG counters.

Parameters:

name - the counter name.

Returns:

the StrongCounter instance.

Throws:

CounterException - if unable to retrieve the counter.

CounterConfigurationException - if the counter configuration is not valid or it does not exists.

getWeakCounter

WeakCounter getWeakCounter(String name)

Returns the WeakCounter with that specific name.

If the WeakCounter does not exists, it is created based on the CounterConfiguration.

Note that the counter must be defined prior to this method invocation using defineCounter(String, CounterConfiguration) or via global configuration. This method only supports CounterType.WEAK counters.

Parameters:

name - the counter name.

Returns:

the WeakCounter instance.

Throws:

CounterException - if unable to retrieve the counter.

CounterConfigurationException - if the counter configuration is not valid or it does not exists.

defineCounter

boolean defineCounter(String name,
 CounterConfiguration configuration)

Defines a counter with the specific name and CounterConfiguration.

It does not overwrite existing configurations.

Parameters:

name - the counter name.

configuration - the counter configuration

Returns:

true if successfully defined or false if the counter exists or fails to defined.

undefineCounter

void undefineCounter(String name)

It removes the counter and its configuration from the cluster.

Parameters:

name - The counter's name to remove

isDefined

boolean isDefined(String name)

Parameters:

name - the counter name.

Returns:

true if the counter is defined or false if the counter is not defined or fails to check.

getConfiguration

CounterConfiguration getConfiguration(String counterName)

Parameters:

counterName - the counter name.

Returns:

the counter's CounterConfiguration or null if the counter is not defined.

remove

void remove(String counterName)

It removes the counter from the cluster.

All instances returned by getWeakCounter(String) or getStrongCounter(String) are destroyed and they shouldn't be used anymore. Also, the registered CounterListeners are removed and they aren't invoked anymore.

Parameters:

counterName - The counter's name to remove.

getCounterNames

Collection<String> getCounterNames()

Returns a Collection of defined counter names.

Returns:

a Collection of defined counter names.